Methods for flotation of ores

ABSTRACT

A method for flotation of non-ferrous ores which includes flotation of said ore with separation of a bulk concentrate and tailings. The bulk concentrate produced is then conditioned with a desorbate agent containing a substance with the general chemical formual

United States Patent 1 Konev et a1.

11 1 3,759,386 1 Sept. 18, 1973 METHODS FOR FLOTATION 0F ORES [76] Inventors: Vyacheslav A|x5i1doiii'i(6i1ev,

Gavanskaya ulitsa, 16, kv. 6; Vladimir Ilich Ryahoi, Kostromskoi prospekt, 39, kv. 2, both of Leningrad, U.S.S.R.

221 Filed: Oct. 23, 1910 21 Appl. No.: 83,647

[30] Foreign Application Priority Data Oct. 23, 1969 U.S.S.R 1370210 [52] US. Cl. 209/167 [51] Int. Cl 803d 1/02 [58] Field of Search 209/166, 167

[5 6] References Cited UNITED STATES PATENTS 1,988,052 l/1935 Schafer 209/166 2,492,936 12/1949 Nokes 209/167 2,608,298 8/1952 Arbiter 209/167 2,811,255 10/1957 Nokcs 209/167 FOREIGN PATENTS oli APPLic ArioNs '9 120,787 5/1958 U.S.S.R.......... 209/166 123,098 3/1958 U.S.S.R.......... 209/166 OTHER PUBLICATIONS .Chem. Abst., 68, 1968, 116535 m, pg. 112.

Chem. Abst., 70, 1969, 59,801 k, pg. 139.

Primary ExaminerFrank W. Lutter Assistant Examiner-Robert Halper Attorney-Holman & Stern wherein X is the second radical.

or sulphur. After this the bulk concentrate conditioned with said agent is subjected to selective flotation. Prior to selective floation it is expedient to add a reagent reducing the pH of the pulp.

2 Claims, No Drawings METHODS FOR FLOTATION F ORES This invention relates to the area of mineral processing, and more particularly, to methods for flotation of ores containing non-ferrous metals such as zinc, lead, copper and molybdenum.

Well known are methods for flotation of polymetallic and lead-zinc ores, including selective flotation of leadand copper minerals into a concentrate with subsequent recovery of zinc minerals.

For this purpose all the ore being processed is to be subjected to fine grinding for liberation of minerals, and for separation of useful constituents from each other and from the gangue. The process of grinding is power consuming, furthermore wear of grinding media and equipment is considerable. All the ore flow treated is repeatedly subjected to flotation with the use of different agents for consecutive separation of useful constituents from the ore.

It is preferable first to separate all the sulphides containing useful metals from the gangue amounting to 90 percent of the ore weight and to exclude this component from further treatment. I

Also, the advantage of preliminary bulk flotation of sulphides is obvious too, as for theirseparation from the gangue by flotation, only coarse grinding is sufficient.

However, the sulphides first separated simultaneously are more difficult to separate later on from each other, because they are covered with a collector agent layer, feature similar flotation properties and yield only partially to the action of depressing agents.

To facilitate the action of depressing agents upon the sulfides, they are floated into a bulk concentrate at a collector agent quantity less than optimal, but this floating leads to their losses into tailings.

It has been attempted to separate a bulk concentrate from the ore to condition it with sodium sulphide and to subject it to treatment in classifiers and thickeners for washing off the reagents. However, this method too requires a considerable consumption of reagents (sodium sulphide) while classifiers and thickeners require large operation areas, and, consequently involve considerable capital investments and operational costs. In addition non-ferrous metals are lost in thethickener overflow.

The object of the present invention is to eliminate the difficulties previously mentioned.

The principal object of this invention is the provision of a method for flotation of non-ferrous ores which will ensure the improvement in grade and quantity of flotation concentrates produced, and will be more economically practicaland easy to realize.

Said principal and other objects of the invention will be achieved through the realization of the hereinproposed method forflotation of non-ferrous ores, including: flotation of said ore with the separating of the bulk concentrate and tailings, conditioning of the bulk concentrate, obtained according to the invention, with an agent-desorbate containing a substance with the general chemical formula where X is sulphur or the second radical and selective flotation with known reagents, of the bulk concentrate conditioned with the agentdesorbate.

Such a method ensures the production of more pure concentrates of metals, as well as their more complete recovery. In addition no washing of the bulk concentrates is required for the removal of agents, and thus losses of useful constituents in the overflow are avoided, no extra equipment such as classifiers and thickeners is needed, and thus the operation is not cumbersome. In consequence, capital investments and operational expenses are reduced.

While carrying out the method, it is expedient to use as an agent-desorbate the product of reaction of sodium sulphide with phosphorus trichloride.

Such an agent ensures the required rate'of the collector desorption from the minerals to be separated at a relatively small consumption of the desorbate agent.

It is very expedient, prior to selective flotation to add to the bulk concentrate conditioned with the desorbate agent a reagent reducing the pH of the pulp.

This will ensure a more complete description of the collector from the surface of the minerals depressed.

Sulphuric acid may be used as an agent reducing the pH of the pulp. This will allow a reduction in the cost of such agents. J i

In order'to explain the invention, an example of the proposed method of realization is described below.

An ore containing lead, zinc and pyrite is subjected to bulk flotation with potassium butyl xanthogenate as a collector. Thus a bulk concentrate and final tailings are obtained. This bulk concentrate is conditioned for 5 minutes with a solution of a desorbate agent containing a substance with the chemical formula x-ae s where X is the second radical of The 'zrmeagtrfrs'fiaaica as a resultbf tl'ie interaction of technical sodium sulphidewith phosphorus trichloride. The desorbate agent consumption amounts to 400-500 g per ton of bulk concentrate (50 g/t of ore in terms of Na,P,S,). Following this, sulphuric acid as an agent for reducing the pH of the pulp pH is added to the bulk concentrate and conditioned for 10 minutes. The sulphuric acid consumption amounts to l500-2000 g per ton of bulk concentrate (l50-200 g/t of ore). Subsequently depressors used usually for .sphalerite and pyrite are added to the pulp: sodium cyanide 1000 g per tort of bulk concentrate g/t of ore) and zinc sulphate 3500 g per ton of bulk concentrate (350 g/t of ore) as well as sodium hy- 40 g per ton of bulk concentrate (4 g/t of ore) and a frother are added till normal froth is formed, following which lead flotation is carried out.

While effectuating the procedure the use of the de- The data of Table I show that, where the present method was used, the results obtained were better than those obtained with the known method. Thus lead content in the lead concentrate was 6.32 percent higher sorbate agent, more oxidation-resistant than sodium 5 and lead recovery into lead concentrate 0.7 percent sulphide, allows the taking advantage of the selectivity higher, while zinc losses in the lead concentrate were of the very process of the collector desorption from the g} Percent lowersurface of sulphides, thus improving the technological TABLE 2 data of the subsequent separation of useful minerals.

Said agent is a stronger desorbate of xanthogenate l0 ITURE FOR AGENTS from the surface of sulphide minerals than sodium sul- Methods Agent Agent COS! Expenses phlde, thus allowing a considerable reduction m the consumpper for each .consumption of the agent-desorbate. 2} The elimination of the operation of washing off the per tox i agent initial agents avoids the considerable capital investments and i bulk Rubles bu k operational expenses required for such washing, and g: g' excludes metal losses in the overflow of the washing Rubles thickeners. Furthermore, it thus becomes possible to regulate and maintain at an optimum degree the collec- The data in Table 2 show that the expenses for agents tor removal from the surfa e of mineral to b afor the present method are 4.5 times lower than for the rated. known method.

Tests have shown that the results of the use of the present method for the flotation of non-ferrous ores w claim: can be considerably better than those obtained when A method f flotation of Sulfide minerals which using other methods. These results are shown in Tables comprises; subjecting an ore to fl tati i a ll 1 and they refef to Separatlon f galena 9 tor reagent to separate a bulk sulfide concentrate and sRhaleme and P earned both m conformlty tailings, conditioning the bulk concentrate with a dethe Prestmt h and the known m sorbate agent for ,said collector containing an inorganic based on the desorption of the collector by sodium sulhexathiohypophosphate compound extracting the Phlde z consumption bemg 7000 8 P of bulk uid phase of the conditioned bulk concentrate, diluting F followed y washing off the agents (the the thickened product with fresh water, and subjecting washing off rate being 116) the obtained ready bulk concentrate to selective flota- TABLE I tion of a sulfide mineral. l 2. The method as claimed in claim 1, wherein said de- Comparlson of bulk separatlon' results sorbate agent is the product obtained by the reaction after the removal of the collector in conformity with f sodium lfid with phosphorus trichloride the present and the known methods.

Content Recovery, percent percent Weight, Methods Flotation product percent Lead Zinc Lead Zinc Known Lead concentrato.- 22.96 53.19 5.33 95.00 9.20 1 Lead flotation i Tailings 77. 04 0.84 16.23 5.00 90.80 1 Bulk concentrate.-. 100.00 12.86 13.77 100.00 '100. ()0 Present Lead concentrate. 17. 40 59. 5.48 95.70 7.

Lead flotation. Taillngs 82.60 0. 60 14.34 4.30 92.55 Bulk concentrate 100.00 10.81 12.76 100.00 100. 

2. The method as claimed in claim 1, wherein said desorbate agent is the product obtained by the reaction of sodium sulfide with phosphorus trichloride. 